Service provider networks typically deliver services, such as digital television, high-speed Internet, Voice-over-IP (VoIP), etc., to customer premises. Service provider networks, including cable networks, have, in recent years, moved beyond merely broadcasting television signals over a coaxial cable to subscribers in their homes. The networks typically carry bi-directional traffic. For example, in addition to receiving data and broadcasts, subscribers of a cable network have a modem allowing the transmission of digital signals upstream toward a headend of the network. Among many services afforded by cable modems are Internet services, voice-over-Internet-Protocol (VoIP) phone services, etc.
A typical cable network is a two-way hybrid fiber-coaxial (HFC) network that supports point-to-multipoint transmission in the downstream direction using digital signals or a mix of analog and digital signals, and multipoint-to-point transmission in the upstream direction. Downstream signals, which carry broadcast digital TV signals, Internet traffic, etc., are distributed via a fiber optic connection from a head-end to a node that converts the optical signals to electrical signals and then distributes the signals to customer premises via a tree and branch coaxial cable distribution network termed ‘cable plant’. Recently, service providers are running fiber to the customer premises to improve bandwidth. At the customer premises, terminal equipment, including cable modems, supports the delivery of downstream services. Upstream signals from the customer premises propagate from the branches of the cable plant towards the headend of the network. The upstream and downstream signals are prone to impairments originating at various locations in the network. There may be numerous devices, cable segments and connectors located between the fiber optic node and the customer premises equipment where defects can occur, and defects and impairments can occur at different customer premises that can impact the signal quality of other customer premises.